Question for you techies - CPU temperature

[Otlecs]

So, I have a shiny new liquid-cooled machine, based around a (pseudo!)quad core Intel Core 2 Extreme QX9650 (3.67Ghz factory overclocked, 1333MHz FSB, 12MB cache).

My question is... what would you expect the operating temperature range to be, measured per-core? Using a variety of tools, it seems each of my cores are running at >100c when multi-boxing.

I've had a good Google, and even looked at the Intel thermal characteristics datasheet for the chip, and so far as I can tell that's WAY too hot, although everybody seems to report higher than normal temperatures and a wide spread of temperatures at idle (which I also see... between 50 and 70 at complete idle with SpeedStep disabled).

The system is stable. The cooling pump is operating at 100% according to the provided monitoring software. The radiator leading to the ceramic cooling block is clear. There's plenty of space all around the machine.

Under this sort of load, the huge array of fans in the box are operating at between 100% (CPU front), 65% (CPU rear) and 40% (jet turbine-like fan at the front). The other fans are all operating at less than 50%.

Thanks in advance for any thoughts / suggestions.

[Codam]

So, I have a shiny new liquid-cooled machine, based around a (pseudo!)quad core Intel Core 2 Extreme QX9650 (3.67Ghz factory overclocked, 1333MHz FSB, 12MB cache).

My question is... what would you expect the operating temperature range to be, measured per-core? Using a variety of tools, it seems each of my cores are running at >100c when multi-boxing.

I've had a good Google, and even looked at the Intel thermal characteristics datasheet for the chip, and so far as I can tell that's WAY too hot, although everybody seems to report higher than normal temperatures and a wide spread of temperatures at idle (which I also see... between 50 and 70 at complete idle with SpeedStep disabled).

The system is stable. The cooling pump is operating at 100% according to the provided monitoring software. The radiator leading to the ceramic cooling block is clear. There's plenty of space all around the machine.

Under this sort of load, the huge array of fans in the box are operating at between 100% (CPU front), 65% (CPU rear) and 40% (jet turbine-like fan at the front). The other fans are all operating at less than 50%.

Thanks in advance for any thoughts / suggestions.

That's way too hot. So much so that I can't belive its a correct reading if your machine is stable. To start off with, CPU temperatures wouldn't stabilise at 100 C. To reach that high, you would not be dissipating anywhere near enough heat, and the temps would continue to rise until something broke.

Specfically which tools are you using to measure? There is often another reading in addition to the core temperature called T junction or something similar, this is nothing to take any notice of. Personally I prefer core temp http://www.alcpu.com/CoreTemp/. (in the picture on that page you see the T junction reading I was referring to as "Tj. max")

[Ðeceased]

something is seriously messed up there m8y. u should be looking at 50C for full load under liquid cooling! Hell my brother is running his 9650 under an IFX-14 passive cooling and getting 50C under full load.. (not overclocked)

Either there is a horrible thermal paste application under that thermal pad or the temp reading is way off.. I can't see how +100C is at all possible, which suggests the temperature reading is off.

hope it gets sorted out soon

Ð

[Otlecs]

Well, that at least confirms my suspicions that there's something seriously amiss here.

I'll open a support call... not that I expect them to do anything useful, based on experience to date.

Specfically which tools are you using to measure?

The system comes with some nVidia monitoring software installed. Yes, that's system monitoring software, not graphics card monitoring... the cards are both 1GB ATI cards!

I also installed Avalanche, which gave the same readings and finally installed CoreTemp on the advice of a friend. That's quite neat actually - it puts the temperature readout on the LCD screen of my G15 (at last... something useful on there!!).

It shows the same temperatures, and identifies Tj.max as 100C as I recall.

So all three measuring tools show the same numbers. I've heard anecdotal evidence of "sticky" temperature sensors on these chips, but that's not very reassuring.

In fact, I checked when I was home at lunchtime and the front CPU fan is running at a constant 100%, even at idle. I also enabled SpeedStep in the BIOS, but the reported temperatures remain the same regardless of SpeedStep, even with no load (which I would imagine indicates a sensor fault, but I'm way outside my knowledge comfort zone here).

So... yes, something very, very wrong there. I'll make the approrpriate sacrifices to the God of Support and then pick up the phone this evening to see what classic lines they have for me this time around.....

Thanks folks.

[Ðeceased]

In fact, I checked when I was home at lunchtime and the front CPU fan is running at a constant 100%, even at idle. I also enabled SpeedStep in the BIOS, but the reported temperatures remain the same regardless of SpeedStep, even with no load (which I would imagine indicates a sensor fault, but I'm way outside my knowledge comfort zone here).

have you checked the temps after having it off for a while.. ie switch it on in the morning and go straight to the BIOS..

I think ur right, it sounds like a faulty sensor to me :S

[Ken]

Indeed:
- as mentioned above: faulty sensor (very likely, because a CPU at 100+ degrees is likely to die before reaching 100)
- you are reading degrees Celcius while you're actually seeing Farenheit values

[Ðeceased]

Indeed:
- as mentioned above: faulty sensor (very likely, because a CPU at 100+ degrees is likely to die before reaching 100)
- you are reading degrees Celcius while you're actually seeing Farenheit values

I wouldn't be surprised if it's some idiot down at manufacturing that's set it to Fahrenheit, yet left the C :P

100F would be around 37ish C which sounds much more like it

[Otlecs]

you are reading degrees Celcius while you're actually seeing Farenheit values

You know, this occured to me when I first looked at the figures, and I re-checked the options at least on the first of the three tools, but I'll check again tonight before calling support.

I'm pretty sure that it's Celcius in all cases though - CoreTemp spammed overheat warnings at me non-stop (each one in a separate pop-up dialogue, bless it.... grrrr....) until I finally got into the options screen to disable the warning.

I wouldn't be surprised if it's some idiot down at manufacturing that's set it to Fahrenheit, yet left the C

Is that something they can calibrate on the chip itself? I always imagined that the chip would report some fixed value that would be converted by the monitoring software.

have you checked the temps after having it off for a while.. ie switch it on in the morning and go straight to the BIOS..

Unfortunately, my BIOS doesn't have a temperature display (it doesn't have much of anything actually!!), so I can only look once I've got Windows up and running. I did that at lunchtime (my machines are always "hard" off when I'm not using them) and the temperatures were immediately and consistenly reported as around 60/70c even after an extended idle period.

As an aside, the ambient temperature here is about 28c, and has been for several weeks. Warm, but surely not warm enough to cook a CPU!

Thanks again for all the ideas. Even if it's a faulty reading, I expect the CPU to be replaced under warranty.

I imagine that the variable rate cooling system (coolant pump, fans, etc) will work off those values and the whole point of coughing up for liquid cooling was for a quiet machine. Having any of the fans running at 100% even at idle sort of defeats that. Oh, unless that particular fan isn't variable speed. Hmmm.....

I knew there was a reason why I usually go for "sweet spot" instead of "cutting edge" machines

[Ughmahedhurtz]

As mentioned, that's definitely too hot. Operating spec for most modern CPUs from AMD/Intel are up to 100C. A couple of things to verify: do you have an air bubble in the cooling system; did you get the thermal paste put on good underneath the heat block; is your coolant circulating.

[Otlecs]

A couple of things to verify: do you have an air bubble in the cooling system; did you get the thermal paste put on good underneath the heat block; is your coolant circulating.

I have no idea how to verify any of those things - it's a Dell XPS730 and all I know is that it looks pretty and goes fast

I've avoided mentioning the D word before because I know I'm going to get a load of "oh well, what do you expect", but living overseas and wanting an English language everything left me with few choices!

I'll let them sort it out.

Ever the optimist....